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Journal of General Internal Medicine Apr 2016Increasingly, performance metrics are seen as key components for accurately measuring and improving health care value. Disappointment in the ability of chosen metrics to... (Review)
Review
Increasingly, performance metrics are seen as key components for accurately measuring and improving health care value. Disappointment in the ability of chosen metrics to meet these goals is exemplified in a recent Institute of Medicine report that argues for a consensus-building process to determine a simplified set of reliable metrics. Overall health care goals should be defined and then metrics to measure these goals should be considered. If appropriate data for the identified goals are not available, they should be developed. We use examples from our work in the Veterans Health Administration (VHA) on validating waiting time and mental health metrics to highlight other key issues for metric selection and implementation. First, we focus on the need for specification and predictive validation of metrics. Second, we discuss strategies to maintain the fidelity of the data used in performance metrics over time. These strategies include using appropriate incentives and data sources, using composite metrics, and ongoing monitoring. Finally, we discuss the VA's leadership in developing performance metrics through a planned upgrade in its electronic medical record system to collect more comprehensive VHA and non-VHA data, increasing the ability to comprehensively measure outcomes.
Topics: Electronic Health Records; Health Services Accessibility; Humans; United States; United States Department of Veterans Affairs; Veterans Health
PubMed: 26951272
DOI: 10.1007/s11606-015-3559-0 -
Atlanta Journal-record of Medicine Nov 1899
PubMed: 36019224
DOI: No ID Found -
The Dental Register Nov 1890
PubMed: 33699748
DOI: No ID Found -
Current Research in Neurobiology 2022The firing maps of grid cells in the entorhinal cortex are thought to provide an efficient metric system capable of supporting spatial inference in all environments.... (Review)
Review
The firing maps of grid cells in the entorhinal cortex are thought to provide an efficient metric system capable of supporting spatial inference in all environments. However, whether spatial representations of grid cells are determined by local environment cues or are organized into globally coherent patterns remains undetermined. We propose a navigation model containing a path integration system in the entorhinal cortex and a cognitive map system in the hippocampus. In the path integration system, grid cell network and head direction (HD) cell network integrate movement and visual information, and form attractor states to represent the positions and head directions of the animal. In the cognitive map system, a topological map is constructed capturing the attractor states of the path integration system as nodes and the transitions between attractor states as links. On loop closure, when the animal revisits a familiar place, the topological map is calibrated to minimize odometry errors. The change of the topological map is mapped back to the path integration system, to correct the states of the grid cells and the HD cells. The proposed model was tested on iRat, a rat-like miniature robot, in a realistic maze. Experimental results showed that, after familiarization of the environment, both grid cells and HD cells develop globally coherent firing maps by map calibration and activity correction. These results demonstrate that the hippocampus and the entorhinal cortex work together to form globally coherent metric representations of the environment. The underlying mechanisms of the hippocampal-entorhinal circuit in capturing the structure of the environment from sequences of experience are critical for understanding episodic memory.
PubMed: 36685760
DOI: 10.1016/j.crneur.2022.100035 -
American Journal of Physiology.... Feb 2013Analysis of the interactive effects of combinations of hormones or other manipulations with qualitatively similar individual effects is an important topic in basic and... (Review)
Review
Analysis of the interactive effects of combinations of hormones or other manipulations with qualitatively similar individual effects is an important topic in basic and clinical endocrinology as well as other branches of basic and clinical research related to integrative physiology. Functional, as opposed to mechanistic, analyses of interactions rely on the concept of synergy, which can be defined qualitatively as a cooperative action or quantitatively as a supra-additive effect according to some metric for the addition of different dose-effect curves. Unfortunately, dose-effect curve addition is far from straightforward; rather, it requires the development of an axiomatic mathematical theory. I review the mathematical soundness, face validity, and utility of the most frequently used approaches to supra-additive synergy. These criteria highlight serious problems in the two most common synergy approaches, response additivity and Loewe additivity, which is the basis of the isobole and related response surface approaches. I conclude that there is no adequate, generally applicable, supra-additive synergy metric appropriate for endocrinology or any other field of basic and clinical integrative physiology. I recommend that these metrics be abandoned in favor of the simpler definition of synergy as a cooperative, i.e., nonantagonistic, effect. This simple definition avoids mathematical difficulties, is easily applicable, meets regulatory requirements for combination therapy development, and suffices to advance phenomenological basic research to mechanistic studies of interactions and clinical combination therapy research.
Topics: Animals; Dose-Response Relationship, Drug; Drug Synergism; Endocrine System; Energy Metabolism; Homeostasis; Hormones; Humans; Models, Biological
PubMed: 23211518
DOI: 10.1152/ajpendo.00308.2012 -
Entropy (Basel, Switzerland) Jul 2021Efficiently accessing the information contained in non-linear and high dimensional probability distributions remains a core challenge in modern statistics....
Efficiently accessing the information contained in non-linear and high dimensional probability distributions remains a core challenge in modern statistics. Traditionally, estimators that go beyond point estimates are either categorized as Variational Inference (VI) or Markov-Chain Monte-Carlo (MCMC) techniques. While MCMC methods that utilize the geometric properties of continuous probability distributions to increase their efficiency have been proposed, VI methods rarely use the geometry. This work aims to fill this gap and proposes geometric Variational Inference (geoVI), a method based on Riemannian geometry and the Fisher information metric. It is used to construct a coordinate transformation that relates the Riemannian manifold associated with the metric to Euclidean space. The distribution, expressed in the coordinate system induced by the transformation, takes a particularly simple form that allows for an accurate variational approximation by a normal distribution. Furthermore, the algorithmic structure allows for an efficient implementation of geoVI which is demonstrated on multiple examples, ranging from low-dimensional illustrative ones to non-linear, hierarchical Bayesian inverse problems in thousands of dimensions.
PubMed: 34356394
DOI: 10.3390/e23070853 -
British Medical Journal Mar 1953
Topics: Metric System; Weights and Measures
PubMed: 13019151
DOI: No ID Found -
Entropy (Basel, Switzerland) Aug 2022In this paper, we present the concept of the logical entropy of order , logical mutual information, and the logical entropy for information sources. We found upper and...
In this paper, we present the concept of the logical entropy of order , logical mutual information, and the logical entropy for information sources. We found upper and lower bounds for the logical entropy of a random variable by using convex functions. We show that the logical entropy of the joint distributions X1 and X2 is always less than the sum of the logical entropy of the variables X1 and X2. We define the logical Shannon entropy and logical metric permutation entropy to an information system and examine the properties of this kind of entropy. Finally, we examine the amount of the logical metric entropy and permutation logical entropy for maps.
PubMed: 36141060
DOI: 10.3390/e24091174 -
EJIFCC Oct 2019Globally, laboratories are producing, communicating, and exchanging millions of laboratory examination values to multiple parties every day. For most values,... (Review)
Review
Globally, laboratories are producing, communicating, and exchanging millions of laboratory examination values to multiple parties every day. For most values, 'measurement units' are required to make the numerical values comparable and meaningful. However, a non-systematic use of 'measurement units' can create errors in communication between health care providers and become a risk to patient safety. Therefore, the Committee of Nomenclature for Properties and Units (C-NPU) recommends using an unambiguous terminology of 'measurement units', for daily patient care and scientific publications. In this work, C-NPU summarizes the recommendations on 'measurement units', explaining the reasons and the principles of the 'measurement units' used in laboratory medicine.
PubMed: 31695584
DOI: No ID Found -
The Southern Medical Record Jun 1876
PubMed: 36023278
DOI: No ID Found